Efficiency vs Fun

I was browsing WoW Insider, as I tend to do on slow days at work, when I happened across an article, and I kind of skimmed it for the meat of the matter:

"But are players too focused on efficiency over fun? Would WoW be a happier place if we stopped to smell the roses along the leveling path, particularly, just because roses are awesome? And are you focused on efficiency over fun or self-improvement? Think about it before answering, I know I had to."

This got me thinking: How often do I sacrifice fun for efficiency? Will I switch to a different class in Dragon's Dogma simply to beat something a little faster, regardless of how enjoyable that class is? Will I stop using a weapon in Persona 4 Golden that has a chance to randomly debuff an enemy just because it doesn't do as much damage as that plain ol' sword?

How often have I powered through quests in an MMO just to get to the next level, just to get a slightly better weapon, just to get some silly achievement?

About 2 weeks ago, I got an email from Blizzard, inviting me back to try out Mists of Pandaria for 10 days. Part of me groaned at the thought of even setting foot in the game again, part of me wanted to toss all the money I had on my characters at my brother and run away quickly, and the rest of me simply wanted to see what was new, and see what was changed.

Long story short: I found myself in the new expansion content, powering through quests without paying much attention to the hows & the whys. Then I stopped. I looked around, and noticed that I was simply chasing numbers... I suppose I was chasing efficiency in the game, and not actually having fun.

So how about the rest of you? How much fun are you willing to sacrifice in order to be efficient in a game? When does the cut off point come up where you go "Yeah, I'll have to get rid of this completely crazy gun in Borderlands 2 because this one is just so much stronger, even if its a bit boring"?